Initial player tests.

These are a very good start to getting player tests written and are
based largely on the tests for the other models.  I'm sure there will
need to be additional tests written as we find unique use cases for
this model that we haven't really tried to consider, yet.
Merge branch 'master' of https://github.com/geisler/game_contest_server into gmaster
Merge branch 'gmaster' into dev
Added new tests. 58.
Uploadable concern. 60. Not sure where the extra 2 came from. 60.
Just passing some stuff. ~25.
More changes. Can't get it to add a new player. 18.